The present invention relates to postage metering systems wherein funds are credited to a secure electronic vault within the postage meter and wherein funds are accounted for by debiting from the vault in accordance with the postage value during each posting transaction and, more particularly, to means of inspecting the postage meter to detect any attempts to tamper with the vault for the purpose of fraudulently obtaining a posting transaction without accounting for dispensed funds.
A known postage meter system is comprised of a printing unit in electronic communication with a micro-controller system located within a secure housing. The micro-controller system is comprised of a number of memory units, for example, a program memory and number of non-volatile accounting memories. The micro-controller system includes electronic provisions for securing accounting data within the non-volatile accounting memories which accounting data represents the funding transactions performed by the meter. Generally, this security has been provided by physically placing the printing unit and the accounting vault within the same secure housing and providing tamper revealing devices, that is, devices which physically reveal if the housing has been tampered with, such as, brake-off screws and paper seal strategically located at access points on the housing. The micro-controller control system also includes programming to permit secure telecommunication between a micro-controller system and a remote location such as a data center. Communication between a data center and the respective meter is undertaken for the principle purpose of recharging funding registers within the non-volatile accounting memory units of the meter. Security for the telecommunications is generally provided by utilizing encryption techniques and special communication protocols, along with a process of account reconciliation between information in the meter's non-volatile memories and the data center.
To insure the integrity of the postage meter, it is known to require periodic visual inspections of every meter in public use for the purpose of detecting any evidence of tampering. The inspection process, as presently undertaken, presents several disadvantages. The process requires the maintenance of costly inspection procedures and personnel of both the manufacturer, in the case of on-site inspection, and the postal authorities, in maintaining postal inspection centers. Visual inspections are less reliable to detect electronic invasion of the accounting system. The cost and logistical burdens of visual inspection are substantially greater with the introductions of new technologies for developing electronic postage meters which are particularly intended for use by small businesses and individuals.
A collateral concern affecting meter operation relates to the proper operation of the meter. For example, a postage meter printing system may periodically operate improperly which can result in the meter accounting for expended funds when in fact the posting funds were not printed due to printer malfunction. The periodic malfunction or mis-function of the postage meter can cause improper funds accounting which generally represent lost funds to the user.
It is known to provide the meter micro-controller system with the capability of maintaining an error log of detected system errors. It is known to provide a system repair person, with the aid of special equipment, to communicate with the micro control system of a meter through an external interface port during an on-site service call. The service repair person is then allowed to access the error log and retrieve the information stored therein. From that information, it is hoped that proper machine operation can be verified and potential system operation malfunction anticipated. By anticipating the onset of system malfunction, it is intended the occasions promoting system errors can be immediately corrected and, thereby, minimize the potential for system error resulting in lost funds. Further, in relationship to specific types of errors which have already occurred, verification of the error condition may permit some funds recovery.